The invention discloses a dual-ring hairpin probe mediate
label-free strand displacement amplification method for detecting
bleomycin. The method includes the steps that when
bleomycin exists, a dual-ring hairpin probe fractures at a recognition site, and a triggering sequence is released; the triggering sequence and a ring part of a
signal probe are combined and subjected to a strand displacement amplification reaction under the effect of a
polymerase and a
nicking enzyme, and finally a great number of G-four-chain sequences are generated. At the same time, a primer chain extends to open the
signal probe, and therefore the G-four-chain sequences packaged in the neck of the
signal probe can be exposed. Finally, NMM molecules are bound to the G-four-chain sequences to generate
fluorescence signals, and
bleomycin is quantified through the detected
fluorescence signals. As the triggering sequence is designed at the neck of the dual-ring hairpin probe, background signals of a detection
system are reduced; by combining bleomycin
cutting and the strand displacement amplification reaction, bleomycin can be detected sensitively, and the
detection limit is 0.34 nm. The method has the advantages of being easy to operate, free of labeling and good in specificity.